1. Field of the Invention
This invention relates generally to rolling mills for rolling products such as rods or bars. The invention is concerned in particular with a rolling mill roll stand incorporating improved means for adjusting the operative positions of the work rolls in relation to each other as well as in relation to the mill pass line.
2. Description of the Prior Art
In a rolling mill of the above-described type, for example a single strand bar mill, a plurality of vertical and horizontal roll stands are arranged in an alternating sequence along the rolling line. Each roll stand has a roll housing containing a pair of work rolls. The work rolls have multiple grooves defining a plurality of roll passes. When an active roll pass becomes worn, the rolling operation is temporarily interrupted and another roll pass is aligned with the mill pass line by shifting the roll housing in the direction of the roll axes. Thereafter, as rolling continues, the cross-section of the rolled product is monitored closely. If prescribed tolerances are not being achieved, then further roll adjustments are made. These adjustments can comprise one or more of the following: an axial shifting of one roll relative to the other roll in order to bring the roll grooves of an active roll pass into proper alignment with each other; an axial shifting of both rolls in order to adjust the alignment of an active roll pass in relation to the mill pass line (as defined by the guides on the roll housings); a symmetrical lateral shifting of both work rolls in order to adjust the spacing or "parting" therebetween. These adjustments are extremely precise. For example, axial roll adjustments are usually on the order of .+-.0.002"-0.125".
The above-mentioned axial roll adjustments are conventionally made manually at each roll stand by employing mechanisms of the type shown in U.S. Pat. No. 3,003,836. However, experience has indicated that it is extremely difficult for operating personnel to make precise adjustments at the rolling line where the environment is characterized by noise, coolant sprays, equipment vibrations, etc. Consequently, the reaction time of operating personnel is frequently too slow, and the resulting adjustments often lack precision. This in turn results in wasteful production of off-gauge unacceptable product.
A further drawback which is particularly characteristic of conventional vertical roll stands is that for various roll adjustment mechanisms and their associated drives are mounted directly on the roll housing in a manner which unduly complicates shifting of the housing away from and back onto the rolling line when roll changes are required.